Nervous system Part 3 Flashcards
what are the 3 subsystems of somatosensory
- cutaneous mechanoreceptor
- proprioception
- pain and temperature
where does mechanosensory information from the upper body enter?
cervical spinal cord - cuneate tract, crosses over contra laterally
where does mechanosensory information from the lower body enter?
lumbar spinal cord- gracile tract, crosses over contralaterally
first synapse of the mechanosensory pathway?
caudal medulla
second synapse of mechanosensory pathway?
ventral posterior lateral thalamic nuclei
two types of proprioceptors?
- muscle spindle- muscle length changes
2. Golgi tendon organ- tension on muscle
muscle spindle groups
group 1a - movement of limbs, rapidly adapting
group 2- static limb position, slowly adapting
nociceptors
receptors that sense pain
A/sigma fiber group
fast pain pathway, intense mechanical or thermal
ex. hitting hand with a hammer
- first pain felt
C fiber group
slow pain pathway, thermal mechanical or chemical
- second pain felt
how are pain signals transducer?
TRPV1 and TRPV2 receptors that flux Na and Ca
which pathway does pain/temp follow?
anterolateral pathway
what are the 3 branches of the autonomic nervous system
- sympathetic (fight/flight)
- parasympathetic (rest/digest)
- enteric
mechanisms for regulating autonomic pathway?
- antagonistic actions: opposite affects
- dual innervention: input from both systems
- basal tone
where do the neurons of the parasympathetic system originate?
close to the target organs (cranial nerves and sacrum)
where do the neurons of the sympathetic system originate?
within the spinal cord (thoracic)
